<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>按钮1</button>
    <button>按钮2</button>
    <button>按钮3</button>
    <button>按钮4</button>
    <button>按钮5</button>
    <script>
        var but=document.querySelectorAll('button')
        for(var i=0;i<but.length;i++){
            but[i].onclick=function(){
                // console.log(11);
                for(var i=0;i<but.length;i++){
                    but[i].style.backgroundColor=''
                }
                this.style.backgroundColor='pink'
            }

        }
    </script>
</body>
</html> 